Grapple



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2 ma i 3,089,726 GRAPPLE Robert G. LeToumeau, P). Box 2307, Longview, Tex. Filed Jan. 18, 1961, Ser. N o. 83,434 1 Claim. (Cl. 294-88) My invention relates to grapple devices, and more particularly to grapple devices of the general ltype wherein opposing pivoted fingers engage a load and are -urged to- Ward the closing position by gravity and load weight, and are powered toward the open position.

The grapple of my invention is especially applicable to logging operations, though by no means con-fined thereto. While there have been numerous grapples devised in the prior ait of which I am aware, none have proven to be entirely satisfactory.

It is accordingly the general object of my invention to provide an improved grapple.

Another object or" my invention is to provide a grapple which shall be capable of attaining a full open position as well as a full closed position.

Another object of my `invention is to provide an irnproved grapple rwherein the suspension cable is the only cable required.

Another object of my invention is to provide an im proved .grapple wherein the grapple may be .positively p-owered to open position.

Another object of my invention -is to provide an improved grapple wherein means for positively powering the grapple to open position is mounted on the grapple itself.

Another object of my invention is to provide a vgrapple with an improved control arrangement.

Another object of my invention is to provide an improved grapple structure.

These and other objects are effected by my invention as will be apparent from the following description taken in accordance with the accompanying drawings, forming a part of this application, in which:

IFlG. l lis a schematic perspective view of a grapple in accordance with a preferred embodiment of my invention;

`FIG. 2 is a side elevational view, partly in phantom, showing the opposite side of the grapple of iFlG. l1;

FIG. 3 is `a schematic side elevational view showing the .grapple of FIG. l in maximum closed position;

iFlG. 4 is an end elevational View of the grapple of FIG. l; and

FIG. 5 is a schematic block diagram showing an electric circuit control arrangement.

`Referring now to the drawings, the grapple, in accordance with a preferred embodiment of the invention, includes a single or middle load handling finger 11, and a pair of double or outer load handling fingers 13, 15. The double load handling ngers 13, l are maintained in rigid parallel spaced relation by a spacer member 17 and a main pivot structure l19. The spacer member L17 extends between the double fingers 113, 15 at their ap-v proximate centers and is fixed, as by Welding, to their inner side surfaces. The load contacting surface 21 of each finger 11, 13, 15 is Iconcave and is approximately a little more than a quarter of a nearly circular ellipse. The fingers are all pivoted adjacent the upper end position of their load contacting surfaces on a main pivot, comprising a pin Z3, and suitable retainer means. A pair of sleeves 25 on the pin 23, one between each outer finger and the middle finger, -act as spacers.

The middle finger 11 has an integral portion which extends laterally beyond the main pivot 19 and which may be termed a closer arm 21. The middle finger d1 also has an integral portion which extends generally upwardly in the general direction of -a tangent to the finger 3,989,726 Patented May 14, 1963 outer profile surface at its approximate center, and which integral extension portion may be termed an opener arm y2x9.

The grapple also includes a bridge structure 31 and a pivot link 33. The bridge structure has a generally horizontal portion made up of a pair of spaced parallel members 35, and -a downwardly and outwardly depending member 37 which is integrally fixed to the parallel members at its upper yend and pivoted to the middle tooth 11 adjacent the juncture of the middle tooth and the opener arm at 39. A pivot link member 33 having the general shape of an isosceles triangle is pivoted at each of its base side apices at 41, 43 to a respective one of the double fingers 13, 15 at its lrear side center region. The pivot link member 33 is pivoted at its apex region at 45 to the bridge structure 31 adjacent the outer end of the .bridge structure.

The grapple is suspended by a single load cable 47, as from a boom (not shown). The load cable 47 bears on a firs-t sheave 49 which is carried by the horizontal portion of the bridge structure 3.1 at its approximate center, and passes downwardly and around a second sheave 511 which is carried by the .cl-oser arm 27 adjacent its outer end. The load cable 47 then passes upwardly and is dead ended on the horizontal portion of the bridge struc-ture Iat 53.

jThe middle finger opener arm 29 is controlled by a cable which is reeled ofi .a drum 57 and fixed at lthe free end 59 to a projection -61 of the opener arm 29. The `cable drum 57 is driven by a reversible electric motor 63 through a gear box 65. The motor 63, drum 57, and gear box assembly 65 `are hxedly mounted on the bridge structure 31. Electric power is supplied to the electric motor via a spring biased reel (not shown), which may be fixed to the boom or other struct-ure (not shown) from which the grapple is suspended. This reel carries an electric conductor cable 67 which supplies power -to the reversible motor 63. The motor 63` is provided with an electromagnetic friction brake 64 of a type such that when the motor is energized, the brake 64 is released, and when the motor is de-energized, the brake 64 is set. Eye rings 69 are provided on the grapple, to which tag lines (not shown) may be secured if desired.

'In PIG. 5 there is shown -in schematic block form a power source 71, which supplies power respectively through a hoist controller 73 to a hoist motor 75 to control movement of cable 47, and through a grapple motor controller 77 to control the grapple motor 63, and hence, movement of cable 55.

In operation, when it is desired to pick up a load, for example a log, the grapple motor 63 is run in the direction to reeve cable 55 onto the drum 57, thus pulling the opener arm 29 toward the motor 63j, forcing the middle grapple finger 11 to move away from the double fingers 13|, 15?, thus opening the grapple. Then hoist cable 47 is reeved out, lowering the grapple down onto the log. The grapple may be oriented relative to the log by means of tag lines (not shown). `Since the weight of the grapple bearing on cable 47 l'tends to move the closer arm 27 upwardly to try to close the grapple, while the tension of cable 55 on opener arm 29 tries to open the grapple, then the grapple will be held in .any degree of open or close by means of the brake 64 when the m-otor 63 is de-enengized. When the grapple has descended into piek-up position on the load, the motor 63' is energized in the reverse direction to reeve out cable 55, while tension lof the hoist cable 47 is utilized to close the grapple fingers 11, 13, 15 onto the load. As the load is picked up, the additional weight on the hoist cable 47 causes the fingers to grip the load harder. Thus, there is no possibility that the load will be released until the motor 63 is energized in the proper direction to open the fingers 11, 13, 15.

Although I have shown my invention in only one form, it will be apparent to those skilled in the art that it is not so limited, but is `susceptible of various changes and modifications without departing from the spirit thereof.

I claim:

A grapple comprising opposed load engaging fingers having a common pivot, a grapple closer arm integral with one of said fingers and extending laterally of `said pivot in the direction away from said nger, a tirst sheave mounted on said closer arm, a grapple opener arm integral with said one finger and extending outwardly therefrom, a bridge structure, a link member, means pivoting said bridge structure at one end to said one nger at the louter center portion thereof, means pivoting one end of said link member to the other end portion of said bridge structure, means pivoting the other end 'of said link member to said other References Cited in the le of this patent UNITED STATES PATENTS 2,639,937 Billings May 26, 1953 2,916,322 Wirkkala Dec. 8, 1959 2,985,481 Janoff May 23, 1961 

